For heat assisted magnetic recording (HAMR), electromagnetic radiation is used to heat a portion of a surface of a magnetic storage medium. This facilitates the subsequent recording of magnetic information in the heated portion of the medium. Heat assisted magnetic recording heads include a component for directing electromagnetic radiation onto the surface of the storage medium, and an associated component for producing a magnetic signal for affecting the magnetization of the storage medium.
Heat assisted magnetic recording utilizes an intense near-field optical source to elevate the temperature of the media. When applying a heat or light source to the medium, it is desirable to confine the heat or light to the track where writing is taking place and to generate the write field in close proximity to where the medium is heated to accomplish high areal density recording. It is desirable to provide an efficient technique for delivering relatively large amounts of light power to the recording medium confined to spots of, for example, 50 nm or less. A variety of transducer designs have been proposed for this purpose.
Light can be delivered to a recording head by placing a laser somewhere in the storage device and using a fiber/waveguide to direct the light to the head. Then the light can be coupled into a waveguide on the recording head.